I am facing an issue with GitHub's Vigilant mode which displays my commits via Node-RED as unverified due to their lack of signature. As a feature request, I would like to suggest the possibility of adding GPG keys similar to SSH keys, and if a key is provided, all commits should be automatically signed. To achieve this on my development machine for my other repos, I use the following shell commands:
You would almost certainly need to know the full path since you probably won't have any of the expected path environment variables set inside the container.
On my Linux system, for example, the git command is actually /usr/bin/git so try an exec with that.